IPS-1 polymorphisms in regulating interferon response in HBV infection.

Single nucleotide polymorphisms (SNP) influence the outcome of antiviral therapy in chronic hepatitis B patients. Interferon β promoter stimulator 1 polymorphisms (IPS-1) regulate interferon (IFN) mediated viral clearance in hepatitis B virus (HBV) infection. In our study, HepG2 and HepG2.2.15 were transfected with different SNP genotype expression vectors of IPS-1 (wild-type, rs17857295, rs7262903 and rs7269320). The production of IPS-1 and IFN were evaluated in these transfected cells. IPS-1 in the HepG2.2.15 cells transfected with rs17857295 or rs7262903 was 37% or 31% lower than that with wild-type transfection (p < 0.001). IFN-β in rs17857295 or rs7262903 transfected HepG2.2.15 cells was 5.4 or 3.7 fold higher than that of wild-type transfection (p < 0.0001). IPS-1 in rs7269320 SNP transfected HepG2.2.15 cells was 40% lower than that of wild-type transfection (p < 0.0001); no significantly different IFN-β was observed between rs7269320 SNP and wild-type transfections. IFN-β expression was > 2 fold higher in rs17857295 transfected HepG2.2.15 cells than HepG2 cells (p < 0.001). The data suggests that host HBV viral clearance is stronger in IPS-1 rs17857295 or rs7262903 SNP genotype patients than wild-type patients. Relatively weak inducible IFN-β production in HBV infected patients with IPS-1 rs7269320 SNP or wild-type may contribute to chronic virus infection.